DE1173797B - Electrophotographic material - Google Patents

Description

Electrophotographic Material The invention relates to an electrophotographic material Material composed of a photoconductive layer and an intimate superficial one Contact with this layer standing conductive surface. There are already electrophotographic, materials composed of a base and a photoconductive layer are known, which as photo semiconductors an inorganic substance such as selenium or zinc oxide, or an organic substance such as antracene, benzidine or a heterocyclic compound of a certain type.

According to an older proposal, poly (N-vinylcarbazole) should also be used as photoconductive substance can be used for electrophotographic material.

The object of the invention is to provide an electrophotographic Material that is characterized by excellent properties and is suitable for use is useful in a wide variety of electrophotographic reproduction processes.

A material according to the invention is characterized in that more than 90 percent by weight of the photoconductive layer is organic polymeric substance with repeating structural units of the following general formula Ql Q2 CHR Z Z 'A CR' Q3 Q4 consists in which A means a simple bond or one of the groups alkylene with 1 to 4 carbon atoms, -CO-, -O-CO-, alkylene-O-arylene, Alkylene-COO-, alkylenarylene, arylene, aroylalkylene, aroyl, carbamoyl, carhamoylalkylene, Carbamoylarylene, R and R 'each a hydrogen atom or an alkyl radical with 1 to 4 carbon atoms, Z a sulfur atom or a single bond, Z 'a methine group or a nitrogen atom, Qt and Q together to close an aromatic Core required atoms and q, and Q4 together to close an aromatic Atoms required in the nucleus, with the exception of a material that is a poly (N-vinylcarbazole) contains.

A few examples of vinyl polymers or Copolymers called, which consist of recurring structural units of the above general formula exist or contain such structural units and the for Preparation of the electrophotographic material according to the invention are suitable.

A. Vinyl polymer poly (9-methacrylyloxyfluoren) poly (N-acrylylylphenothiazine) Poly- [N- (4-acrylyloxyethyl) -phenothiazine] poly- [N- (2-acrylyloxypropyl> phenothiazine] Poly- [N- (allylcarbazole) l poly- (N-2-acrylyloxy-2-methyl- N-ethylcarbazole) poly- (N-2-methacrylyloxypropylcarbazole) Poly- [N- (2-p-vinylbenzoylethyl) carbazole] Poly (N-propenylcarbazole) poly-IN- (acrylyl) carbazole poly [4-vinyl-a- (N-caroazyl) toluene B. vinyl copolymers, in particular vinyl copolymers containing vinyl carbazole units Mol percent of N-vinylcarbazole copolymer of N-vinylcarbazole and vinylidene chloride 85.4 Copolymer of N-vinylcarbazole and 3, 3 ', 5-trimethylisononyl ether 93 Copolymer of N-vinyl carbazole and vinyl acetate. 88.6 copolymer of N-vinylcarbazole and isporopenyl acetate ............................................. 94.5 Copolymer of N-vinyl carbazole and vinyl starate ........................................ ........... 37.5 Copolymer of N-vinylcarbazole and ......................................... ...................... 67.6 Copolymer of N-vinyl carbazole and ethyl acrylate ........................................ .......... 41 Graft copolymer of N-vinyl carbazole and poly (ethyl acrylate) 90.3 emulsion polymer of N-vinylcarbazole and ethyl acrylate ............................................ .......... 94.5 Copolymer of N-vinyl carbazole and n-butyl acrylate. 58.3 copolymer of N-vinyl carbazole and 2-ethyl thexylacrylate .......................................... 51.6 copolymer of N-vinylcarbazole and acrylyloxyethyl diethylamine, 76.6 Copolymer of N-vinyl carbazole and vinyl cinnamate ........................................... ...... 92.5 mixed polymer of N-vinylcarbazole and methyl methacrylate ........................................ ..... 62.7 mixed polymer of N-vinylcarbazole and isobutyl methacrylate. 51.8 mixed polymer of N-vinyl carbazole and lauryl methacrylate 77, 4 copolymer of N-vinyl carbazole and Methacrylyloxyäthyldiäthylamine 9.7 copolymer of N-vinylcarbazole and Acrylonitrile ........ 88 Graft copolymer of N-vinylcarbazole and butyraldehyde acetal of polyvinyl alcohol Copolymer of N-vinyl carbazole and di- (2-chloroethyl) vinyl phosphonate ... 82.4 Copolymer of N-vinylcarbazole and styrene ... . . 49 graft copolymer of N-vinyl carbazole and polystyrene. 27.3 copolymer of N-vinylcarbazole and Vinyl naphthalene ............................................... 47, 1 copolymer of N-vinylcarbazole and anthracene (9.10). . . 91.5 copolymer of N-vinylcarbazole and 2-vinyl pyridine. . . 31.8 Mol% N-vinylcarbazole copolymer from N-vinyl carbazole and 4-vinyl pyridine. 32.4 s copolymer of N-vinyl carbazole @ and N-vinylpyrrolidone ........................................... 69, 1 terpolymer of N-vinylcarbazole, acrylonitrile and styrene .......................................... ... 20 graft copolymer of a terpolymer of vinyl chloride, vinyl acetate and Vinyl alcohol with N-vinyl carbazole .... . . . . 29.4 graft copolymer of a Terpolymers of vinyl chloride, vinyl acetate and maleic anhydride with N-vinyl carbazole . 55.1 The vinyl polymers and copolymers listed above can be prepared by one of the various known polymerization methods be e.g. B. by bead or emulsion polymerization or by polymerization in solution; the Polymerisaiton can by free raclicals, by ion formation or by irradiation, e.g. B. with actinic light. It should be noted that the degree of polymerization is not critical and can vary within wide limits.

As far as the copolymers are concerned, it should also be noted that the proportion of structural units of the general formula mentioned is not critical is and - as can be seen from the above list of copolymers - between 10 and 95% can vary, with the properties of the for the preparation of the copolymers compounds used and the required electrophotographic and / or mechanical properties must be taken into account. The best results are achieved if the proportion of structural units is between 40 and 90e / o.

The production of some of the polymers given in the list above and copolymers are described below, for example; the others Polymers and copolymers can be prepared in an analogous manner according to the general known polymerization techniques are produced.

1. Production of poly (N-allylcarbazole) by polymerization in Solution, whereby the polymerization is initiated by free radicals Das nach Levy, monthly Chemie, 33 (1911j, p. 182, synthesized N-allylcarbazole, the one Melting point of 57 to 580 C, is tert in the presence of 4 ° / Oigem. Butyl peroxide polymerized by heating at 1400 ° C. for 30 hours. The polymer obtained is separated by precipitation in hexane and by dissolving in methylene chloride and again Cases purified in hexane.

2. Production of poly (N-propenylcarbazole) by polymerization in solution, the polymerization being initiated by the formation of ions. For production of sodium amide, 5 l of anhydrous liquid ammonia, 115 g of crushed sodium metal and about 1 g of finely divided Fe (NO3) 3 9H2O (as Catalyst for synthesis) implemented as described by A. I. Vogel in “Practical Organic Synthesis', 3rd Edition, 1956, p. 197. Then 855 g of carbazole added, and the ammonia is distilled off by adding dropwise 3750 cm3 of anhydrous Toluene is added. The mixture is refluxed for 2 hours, then cooled to room temperature and finally with a solution of 675 cm3 of propylene oxide were added to 1250 cm3 of toluene. The mixture thus obtained is heated for a further 2 hours on the reflux condenser, cooled and poured into about 51 ice water poured. The whole thing separates into two layers of liquid; the lower layer contains the crystalline p-oxypropylcarbazole formed. Leave to stand overnight.

The melting point of the separated B-oxypropylcarbazole is 120 to 1210 C. This product is mixed again with water until the neutral reaction of the Washed water, from a mixture of 2500 cm3 ethanol and 600 cm3 water recrystallized and overnight in a ventilated drying chamber at 110? C dried.

A mixture of 1350 g of phosphorus pentoxide and 1350 g of anhydrous benzene were heated on the reflux condenser. A warm, as above in 1350 cm3 of water; free benzene prepared solution of 270 g of 5-oxypropylcarbazole is added over a quarter of an hour. The received The blue-green paste is heated in the reflux condenser for 1 t / 2 hours. The reaction mixture is cooled to room temperature and poured into excess hexane. The educated Precipitate is filtered off and dried. The dry powder is stirring entered in water, and the aqueous suspension formed is slowly treated with sodium hydroxide alkalized. After stirring for one hour, the precipitate is filtered off with suction and washed with water and ethanol washed. The main one consisting of poly (N-propenylcarbazole) Precipitate is purified by dissolving in benzene, filtering and precipitating in methanol.

3. Production of the mixed polymer of ethyl acrylate and N-vinylcarbazole a) Production by emulsion polymerization, the polymerization by free Radicals are initiated A solution of 2 g of sodium lauryl sulfate in 100 cm3 of water is heated to 70 ° C. while stirring and while passing nitrogen through. To this Solution are 35.7 g of vinyl carbazole and 4.6 g of sithyl acrylate and also 400 mg of potassium persulfate added. The temperature rises to 800 C; then the solution is cooled to 700.degree. After the exothermic reaction phase, the solution is again 2 '/ hour to 750 C heated. The emulsion obtained is broken by adding 130 cm3 of acetone, and the precipitate formed is washed with water and methanol and then dried. N O / o found: 6.5, i.e. H. 89.7 mole percent N-vinyl carbazole. b) Manufacture by Polymerization in solution, the polymerization being initiated by free radicals A solution of 29.74 g of N-vinylcarbazole, 6.26 g of ethyl acrylate, 200 mg of azo-bis-isobutyronitrile and 160 cm3 of thiophene-free benzene is under for 8 hours Nitrogen heated to 800 C. After dilution with methylene chloride and precipitation in methanol, 34.3 g of polymer are obtained severed. The viscosity number measured in benzene at 250 ° C. is 0.38 dl / g.

4. Production of the copolymer from methyl methacrylate and N-vinyl carbazole by polymerization in solution, the polymerization by - free radicals It is introduced into a 250 cm3 three-necked flask equipped with a reflux condenser is equipped, a solution of 12.5 g of N-vinylcarbazole, 7.5 g of methyl methacrylate, 100 cm8 of benzene and 120 mg of azo-isobutyronitrile while passing nitrogen through Heated to 750 C for 20 hours. After cooling, the mass is treated with methylene chloride diluted and poured into methanol. The precipitate formed is washed with methanol washed, filtered and then dried.

5. Production of the copolymer of isobutyl methacrylate and N-vinyl carbazole by polymerization in solution A solution. from 12.7 g of isobutyl methacrylate, 17.3 g N-vinylcarbazole, 150 mg azo-bis-isobutyronitrile and 75 cm3 thiophene-free benzene is heated to 750 C under nitrogen for 6 hours. Then this solution becomes 60 mg cm3 of methylene chloride diluted and poured into excess methanol. The educated Precipitate is filtered off with suction, washed with methanol and dried. N ° io: found : 3ç76, d. H.

51.8 mole weight percent N-vinyl carbazole.

6. Production of the graft copolymer from vinyl carbazole and Polyvinyl butyraldehyde acetal by polymerization in solution, the polymerization initiated by free radicals A solution of 10 g of poly (vinyl-n-butyraldehyde acetal), 20 g of N-vinylcarbazole and 0.2 g of azo-bisisobutyronitrile in 11 g of cyclohexanone Heated to 750 ° C. under nitrogen for 24 hours. The reaction mass is in t50 cm3 Dissolved methylene chloride and precipitated in methanol. The precipitate formed will washed with methanol and then dried. N N ° / o Found: 4.6, i.e. H. 63.4 mole weight percent N-vinyl carbazole.

In the preparation of the electrophotographic of the present invention Materials can be used to coat the substrate with the photoconductive layer different techniques can be used.

In practice, the polymeric substances in question are either alone or together with other additives, as described in more detail below, preferably first dissolved or in a suitable organic solvent, e.g.

Benzene, acetone, methylene chloride, dioxane, dimethylformamide or glycol monomethyl ether, or dispersed in a mixture of two or more such solvents. The solution or dispersion thus obtained is applied evenly to the surface of a suitable carrier distributed, for example by centrifugation, spraying, brushing or coating, after which the formed layer is dried so that on the Surface of the support a uniform photoconductive layer is formed. Monomers or mixtures can also be used of monomers and polymers Substances applied to the surface to be coated and in situ by any polymerized, condensed or by a method known in polymer chemistry Bridge binding to be connected.

The thickness of the photoconductive layers is not critical and can vary within wide limits depending on the choice and the special case in question. Good results are achieved with photoconductive layers 1 to 20 thick, preferably from 3 to l01l thick. Layers that are too thin do not have sufficient insulating properties. while layers that are too thick require longer exposure times.

It has been found that photoconductive layers are made of polymeric Substances with recurring structural units of the above general formula are solid adhere to the documents to which they were applied.

The photoconductive layers in the material according to the invention can in addition to one or more of the polymeric substances that consist of recurring There are structural units of the above general formula or such structural units contain, one or more of other photoconductive compounds with contain other physical properties.

For example, it has been found that the results are particularly good can be achieved by using a mixture of one of the polymeric substances, which consist of recurring structural units of the above general formula or contain these, with photoconductive substances such as: the imidazole, indole and oxazole derivatives described in Belgian patent 585 555, in particular those listed in Table 1 under numbers 5, 7, 8, 16, 23, 27 and 37 Links; the stilbene derivatives described in Belgian patent 585,507 in particular those in Table 1 under numbers 2, 5, 6, 8, 11, 13, 14 and 15 listed compounds, also 4-nitro-4'-chlorostilbene; the leuco diaryl methane derivatives, which are described in Belgian patent specification 587,794; the imidazo- (1,2-b) -1,2,4-triazine derivatives, such as 3,6-diphenylimidazo (1 2-b) -1, 2, 4-triazine and 2, 3 6-triphenylimidazo (1,2-b) -1 , 2,4-triazine; Quinoxaline derivatives such as 2- (p-dimethylaminophenyl) -3-phenylquinoxaline and 6,7-diphenyl-2,4-dioxypteridine; the 1,2,3-triazole derivatives, such as 2- (p-sulfophenyl sodium salt) -naphtho (1 , 2-d) -1 2,3-triazole; the 1,3,4-triazole derivatives, as described in the German patent 1,060,260; the oxadiazole derivatives described in the German patent 1,058,836 and in French patent specification 1,258,844, e.g. B.

2,5-di- (p-nitrophenyl-1,3,4-oxadiazole, 2,5-di- (p-aminophenyl) -1,3,4-oxadiazole, also 1,4-di- 2- (5-phenyloxadiazolyl) 1 -benzene; other photoconductive substances, as described in French patent 1 258 844, e.g. B.

Fluorenone, N-Ethylcarbazol-3-aldehyde, 4-Nitrofiuoranthren, Aminochrysen, Alizarin Red (C.I. 58,000), 3,7-di (dimethylamino) thoxanthone-10; Brun Indigosol CRRD (C.I. 73411), Orange Indigosol HR (C.I. 73336), a metal-free chlorinated Phthalocyanine dye, p-aminobenzophenone, tetracyanoethylene, or with polymers Substances as described in French patents 1,254,024 and 1,249,634 are described. For example, beneficial results have been achieved with layers 67 to 99e / o of which consist of the polymeric substances according to the invention, and from 1 to 33% from one or more polyvinyl polymers or vinyl copolymers according to French patent 1 249 634.

In addition, compounds can be present in the photosemiconductor layers that increase general sensitivity and / or sensitivity cause electromagnetic radiation in a certain part of the spectrum.

Suitable compounds that increase the general sensitivity and / or the sensitivity to electromagnetic radiation in the visible part of the spectrum are, for. B. the sensitizing substances described in Belgian patent 585 555, and further: aryl methane dyes, e.g. B. Violet Fuchsine (CI. 42510), Bleu Verdarte (CI 689), Vert Solide Nouveau 3 B (CI 42025), Erythrosine 2 Na (CI 773), Rhodamine B 500 (CI 45 170), Fanal Pink B (C. 1.45 160), Rhodamine 6 GDN (C. 1. 45 160), auramine (CI 41,000), pyronine G (CI. 45,005); Polymethine dyes, e.g. B. 3,3'-Diethylthiacarbecyaninjodid: Az dyes, e.g. B. Eriochrome Blue black R (c. I. 15,705); Azomethine dyes, e.g. B; Bis (p-dimethylaminobenzal) azine; Carbonyl dye, e.g. B. Chloranil, Solway Ultra Blue B (CI 62 055), Alizarine Cyanine Green GWA (C. 1., 61-590); polycyclic connec tions, z. B. nitropyrene, N, N'-di (ß-naphthyl) -p-phenylenediamine, phenanthrene, aatracene, acenaphthol; Phthalocyanine dyes, for example Segnale high turquoise NB (CI 74 160); heterocyclic compounds, e.g. B. N, N'-pentamethylene bis (benzthiazole) perchlorate; inorganic substances, e.g. B. ammonium persulfate, potassium bromate and Sky Blue (CI 77 368) and the radiation-sensitive substances described in French patent 1,259,087.

These compounds are preferably used in an amount of 0.1 to 5% used, based on the weight of the polymeric photolietifiable used Substances.

Finally, other compounds can be present in the photoconductive layer be present which give it and / or the coating liquid the desired properties to lend.

For example, plasticizers such as dibutyl phthalate, dimethyl phthalate, Dimethyl glycol phthalate, tricresyl phosphate, triphenyl phosphate, monocresyl diphenyl phosphate etc., the polymeric substances used in the photosemiconductor layer in amounts from 10 to 30% of the polymer weight are added.

Other known additives including pigments and agents that reduce the Viscosity, aging and heat resistance, oxidation and / or the Gloss can also be used. When choosing these additives one will give preference to those substances which have the dark resistance, the photoconductive ones Do not noticeably affect the layer.

For making the electrophotographic material of the present invention is preferably used as a base for the photoconductive layer an electrically conductive plate or foil used or an insulating plate or foil, which is equipped with an electrically conductive layer. Under an electric conductive plate, foil or layer means a plate, foil or layer, whose specific resistance is lower than that of the photoconductive layer, - d. i.e. generally less than 109 ohm cm. Preferably documents are used whose specific resistance is less than 105 Ohm # cm.

Suitable insulating plates are - among other things, glass plates; on these plates must have a conductive layer, e.g. B. a clear silver, gold or tin oxide layer, are applied; this can e.g. B. by evaporation in a vacuum Suitable insulating foils are, for example, synthetic films macromolecular substances with high specific resistance, e.g. B. the one in the Belgian Polysulfonates described in U.S. Patent 565,478; those in the German patent specification 1 139 272, U.S. Patent 3,028,364 and British Patent 901 605 described polyester; Polystyrene; Polyethylene; Collulose ester, etc, or Paper webs with high specific resistance. The insulating foils must be with a 'conductive layer, e.g. B, a thin metal foil, -with-a-layer, which is a metal powder dispersed in the smallest possible amount of binder contains, or with a thin hydrophilic layer that is hygroscopic and / or containing an antistatic compound and a hydrophilic binding agent.

Suitable hygroscopic and / or antistatic compounds are z. B. glycerine, glycol, polyethylene glycols, calcium chloride, sodium acetate, condensation products of maleic acid2 and polyethylene glycols, citric acid amides, oxypropyl sucrose monolaurate, quaternary ammonium compounds, amine salts of lyophiles. alkyl phosphates, lyophiles dialkyl polyoxyalkylene phosphates and polyoxyalkylene amides.

Suitable hydrophilic binders are e.g. B. gelatin, glue, polyvinyl alcohol, - methyl cellulose, carboxymethyl cellulose, cellulose sulfate, cellulose hydrogen phthalate, Cellulose acetate sulfate, oxyethyl cellulose, polyacrylic acid or colloidal silicon dioxide; a particularly good adhesion between the hydrophilic layer and the hydrophobic To effect polymer film, you can use the polymer film with a suitable Coating adhesive layer, as described in German Patent 975 629 for polyester films, in German patent specification 1 046 488 and Belgian patent specification 563 475 for optionally substituted polystyrene films, in the French patent 1 230 216 and Belgian patent 569 129 for polyalkylene films, in which German patent specification 964 924 for cellulose ester films and one of the Belgian patent specification 573 005 have been chosen for hydrophilic layers, the binding agent being polyvinyl alcohol is used.

Suitable conductive: plates are, for example, plates made of aluminum, zinc, copper, tin; Iron or lead into consideration.

Suitable conductive foils are e.g. b. Films made of polymers. Substances with low resistivity, such as. B. polyamide films or paper with low specific resistance. - Good results are available - when using paper, that contains the hygroscopic and / or antistatic substances described above. These hygroscopic and / or antistatic substances are preferably used Paper is incorporated during its production, either through direct addition to the paper pulp or by post-treatment before or after calendering of the paper webs. The substances can also be incorporated into the paper webs as a result be that on the base paper z a composition is applied that the above described hygroscopic and / or antistatic substances and one of the The hydrophilic binder described above contains very good results If you use paper with a low specific resistance, you can also use that with a layer of polymeric fabric coated to create a smooth surface to maintain and at the same time to avoid that the organic fluid in which the photoconductive substance is dissolved, penetrates into the paper. This layer is allowed however during the. Irradiation department of electrons the end do not prevent the exposed image particles. Suitable layers are e.g. B. 2 up to 10 tal thick and consist of one or more macromolecular compounds; Examples of such compounds are of course resins such as Dammar resin, Elemi resin, gum arabic, manila gum and sandarak resin; microcrystalline waxes; modified natural substances such as cellulose diacetate and cellulose triacetate, cellulose acetobutyrate, Sithyl cellulose, ethyl cellulose stearate or other cellulose derivatives, pentaerythritol polyester or other modified rosins and ester gums; Polymers such as polyethylene, Polystyrene and copolymers of styrene, polyvinyl acetate and copolymers of vinyl acetate, polyvinyl acetals of formaldehyde, acetaldehyde, butyraldehyde, polyacrylic acid esters and polymethacrylic acid esters and coumarone-indene resins; and polycondensates such as glycerol phthalate resins and other glyceryl polyesters, alkyd resins, polyethylene glycol esters, diethylene glycol polyesters, Formaldehyde resins and silicone resins.

If desired, plasticizers can also be added, such as. B. dibutyl phthalate, dimethyl phthalate, dimethyl glycol phthalate, tricresyl phosphate, Triphenyl phosphate and monocresyl diphenyl phosphate, etc. have been given particularly good results achieved by using polysulfonates according to Belgian patent 565478 and of polyesters according to German patent specification 1,139,772, the USA patent specification 3,028,364 and British Patent 901,605.

In addition to the usual types of paper, synthetic paper types can also be used be used, e.g. B. made of polyesters, polyamide fibers or polyacrylonitrile fibers.

Before potting the photoconductive layers, these papers are preferably impregnated with substances that increase their conductivity, e.g. with Polycaprolaktam, the polyester of 2,5-di- (poxyphenyl) -l, 3,49xadiazole and 1Xhlor-3-aminobenzol-4,6-disulfochlorid, a mixed polyamide of hexamethylenediamine, caprolactam, adipic acid and sebacic acid, N-methylene polyhexamethylene adipamide or polyamides.

The electrophotographic materials of the present invention can use themselves in the most varied of procedures based on the exposure and the Discharge of an electrostatic located in or on a photoconductive layer Charge based.

The electrostatic charging of the photoconductive according to the invention Layer can be done by one of the methods known in electrophotography, z. B. by friction with a smooth material, by friction with a material, which has a high electrical resistance, e.g. B. with one with polystyrene coated cylinder, by corona discharge, by contact charging or by Discharge of a capacitor. One placed on the back of the copy material positive charge gives about the same result as one on its front side brought negative charge.

The electrophotographic material is then image-conformed to a suitable one exposed to electromagnetic radiation, the irradiated parts of the layer are discharged and an electrophotographic latent image is formed. Then it will be the electrostatic latent image formed is converted into a visible image, and either on the electrical photographic material on which the latent image was generated, or on some other material on which the electrostatic latent Image, for example, using that described in Belgian patent specification 529234 Method was transferred.

The implementation of the original or transferred latent image into a visible image can be according to any of those known in electrophotography Techniques take place whereby the electrostatic attraction or repulsion of finely divided colored solid substances, for example in a powder or a powder mixture, in an electrically insulating liquid (e.g. in the form of a suspension) or in a gas (e.g. in the form of an aerosol), or of finely divided colored liquid droplets, for example in an electrically insulating Liquid (e.g. in the form of a dispersion) or in a gas (e.g. in the In the form of an aerosol) is used.

By suitable choice of the sign of the charge of the developer powder or the developer liquid can be used in any desired manner from each original make a negative or positive copy.

If copier material and developer powder or developer liquid have the same sign, the powder will only adhere to the discharged places, so that a copy is obtained whose image value is compared with the image value of the original is reversed (positive / negative). If the sign of the material and the developer powder or the developing liquid are different, the individual Image values match (positive / positive).

Except for the development after those in electrophotography in general known methods, other techniques can also be used with success, e.g. B. those in Belgian patent 579725 and French patent 1 247 519 described procedure.

If a colored powder is used to make the latent image visible was used, the generated visible image can be modified, if necessary, according to one of the in methods known in electrophotography, e.g. B. by heat, or be fixed on another carrier, for example that in the Belgian patent 488552 described method, transferred and fixed on this.

It goes without saying that the invention is in terms of use of the new electrophotographic materials by no means to any particular one Embodiment limited, and the exposure technique, the charging method, the eventual transfer, the development method and the fixing method as well as the The materials used for these processes can be adapted to the particular circumstances will.

The electrophotographic materials of the present invention can be used use in reproductive techniques involving rays of electromagnetic or work of a nuclear nature. Therefore it should be noted that in the description and the term "electrophotography" used in the claims should be interpreted broadly and includes both xerography and xeroradiography when the invention covers also relates to processes that involve exposure.

The following examples serve to illustrate the invention without it to restrict.

Example 1 On an aluminum paper backing of 60 g / m2 with a 30 C1 thick aluminum foil is coated, another layer is made of a Solution of the following composition applied: poly- (N-propenylcarbazole) (manufactured as described above) 10 g Bleu Zapon Solide 3 G (C.I. 51005) 12 mg methylene chloride .. 80 m3 tetrahydrofuran ................................. 20 cm3 The dried layer is 5 L thick and adheres very well to the surface. The material obtained will negatively charged by a corona effect at a voltage of 7500 volts and exposed behind a negative microfilm. Requires a 4X linear magnification an exposure time of 2.5 seconds. The latent image formed is dusted made visible with a developer powder, which consists of 100 parts of glass beads and 5 Parts of a colored powder prepared as follows: 2 g pitch, 5 g rosin and 1.5 g of smoky black are ground for 4 hours in a ball mill and then under Stir in a stainless steel vessel heated until the mass melted homogeneously is. After cooling, the solidified mass is ground again in a ball mill, until at least 80% of the grains pass through a sieve with a mesh size of 50 C1. then this fine colored powder is mixed with glass beads in a ratio of 5: 100. That The image produced is strong, sharp and clear.

Example 2 A paper backing of 70 g / m2 is provided with a baryta layer coated, which contains 10 parts of barium sulfate, 1 part of gelatin and 1 part of glycerin. After calendering, the barite layer 10 is> thick.

This material is made by immersion in a solution of the following Coated composition: Poly- (N-propenylcarbacol) (prepared as described above) 6 g copolymer of vinyl chloride, vinyl acetate and vinyl alcohol in a weight ratio 91: 3: 6 4 g methylene chloride ...... .................................... 100 cm3 Rhodamine-B 500 solution (1%) (C.I. 45170) in dimethylformamide. . . . . 10 cm3 After drying, the layer is 9 F thick. After negative charging by a The electrophotographic layer becomes reflective behind a corona effect Original printed on both sides exposed.

When using a light source of 100Watt at a distance of 10 cm an exposure time of 3 seconds is required for this. The latent Image is developed with the powder described in Example 1. The received reversed Image is electrostatically transferred to a sheet of writing paper in a known manner and fixed by the fact that it is set out for 10 seconds trichlorethylene vapors. A strong, legible positive image is obtained.

Example 3 A paper backing of 90 g / m2, which is thick with a 4 µ Polyvinyl acetate layer is coated, is by immersion in a solution of the following composition: Poly- (N-propenylcarbacol) (manufactured as described above) 150 g of chloroform 1 1 11 induline scarlet (C. 1,50080) solution (1% in dimethylformamide 22cm3 after rapid drying with warm air, the Thickness of the layer 7 µ. After negative charging due to a corona effect at high The material obtained behind a paper 4 printed on both sides becomes tension Seconds exposed with a 100 watt lamp at a distance of 10 cm. The development the latent image obtained is exposed by moistening the surface of the surface electrophotographic layer with a dispersion of 1 g of blue printing ink in Petroleum carried out.

The image obtained is very sharp and strong.

Example 4 An unbrushed aluminum foil is made with one layer coated from a solution of the following composition: poly- (N-propenylcarbacol) (prepared as described above) 5 g copolymer of vinyl chloride, vinyl acetate and maleic anhydride in a weight ratio of 85: 14: 1 5g Rhodamine B (C.I.45170) . . mg methylene chloride ... 100 cm3 The dry layer is 5 11 thick and adheres very good on the surface even if the material is severely kinked. This Material is then negatively charged by a corona effect and 1 second behind exposed on a slide with a 100 watt lamp at a distance of 10 cm. The electrostatic latent image is now created by dusting it with a powder mixture the following composition: 100 parts iron powder and 6 parts des dye described in Belgian patent 535,951. A strong positive Image of the original is preserved. After fixation of this image by heat will be the exposed parts of the image with a mixture of 6 parts of ethyl acetate and 4 parts len acetone removed. After moistening the aluminum surface with a solution of 1 g sodium hydroxide and 1 g ethylenediamine sodium tetraacetate in 100 cm3 water get an offset plate that is put on the offset machine without further treatment can be.

Example 5 A film made of polyethylene terephthalate which is 20 y thick and coated with a 2 µ'B thick aluminum film by vacuum evaporation is coated with a solution of the following composition by roller application: Poly (N-propenylcarbazole) (prepared as described above) 12 g methylene chloride ...................................... 100 cm3 1 ethyl-4- [ß- (3 , N-ethylcarbazyl) vinyl] quinolinium iodide ............................... 20 mg The coating takes place in a speed of 8 m / min. With intensive drying with a stream of warm air too strong impairment of the polyethylene terephthalate film by the Solvents the applied layer avoided. The dried layer is 7 µ thick. After a negative charge, use a 100 watt lamp at a distance of 10 cm exposed for 1.2 seconds. By developing with that described in Example 4 Powder, a vivid reproduction of the original is obtained.

Example 6 An aluminum foil laminated on a paper backing is coated with a layer of the following composition by dipping : Poly- (N-allylcarbazole) prepared as described above) ..................................... ........ 5 g copolymer of vinyl chloride, vinyl acetate and maleic anhydride in a weight ratio 85: 14: 1 ............................................ 5 g methylene chloride ......................................... 100 cm3 1% solution of Rhodamine B (CI 45170) in dimethylformamide ................................... .............. 1 cm3 The dried layer is 8 µ thick. After negative charging of the material a corona effect makes it 2.5 seconds behind a transparent original exposed with a 100 watt lamp at a distance of 10 cm. After dusting a clear reproduction is obtained with a colored powder.

Example 7 A paper backing of 90 g / m2 is provided with a baryta layer coated, which contains 10 parts of barium sulfate, 1 part of gelatin and 1 part of glycerin. After this layer has dried, the material is immersed in a solution coated with the following composition: Copolymer of N-vinylcarbazole and ethyl acrylate (prepared by polymerization in solution as described above) .. 10 g Rhodamine B (C.I. 45170) 10 mg methylene chloride .. 70 cm3 toluene 30 cm3 Die dried layer is 8 thick. The formed material is due to a corona effect high voltage negatively charged. Then a microfilm image is applied to the electrophotographic Projected layer.

A linear 4x magnification requires an exposure time of 1 minute with a 75 watt lamp.

The latent image is made visible by a powder mixture, that from 100 parts of iron powder and 5 parts of the color powder prepared as follows is composed: 5 parts rosin, 2 parts pitch and 2 parts smoky black are homogenized for 2 hours in a ball mill, with stirring to a uniform Pulp heated, cooled again and ground further until at least 80% of the finely ground Particles are less than 150 in size. The image obtained is very strong and sure. e5sp ,, iel 8 A paper backing of 90 g / m2 is made by Ein taudlieri in a solution of the following composition: copolymer of N-vinylcarbazole and methyl acrylate. 90 g chloroform .............................................. 1000 cm3 Brilliant Glacier Blue (C.I. 42140) 0.35 g coated and quickly dried. The dried layer is 8 11 thick. The material obtained is caused by a corona effect a voltage of 400 volts, negatively charged and 2 seconds with a 100 watt lamp exposed at a distance of 10 cm behind a slide. Then that will be. formed a latent image by immersing the material in a dispersion for 2 seconds developed from 1 g of blue printing ink in 11 hexane, one being :; strong copy of the Originals is obtained.

Example 9 On a paper backing of 90 g / m2., With a.

If a barite layer of 10 g / m2 is provided, another layer is made a solution of the following composition applied: Copolymer of N-vinylcarbazole and n-butyl acrylate. 12 g methylene chloride ........................................... 100 cm3 Bleu Basique pour Cuir N 2 B (C.I. 51195) 50 mg After rapid drying with Infrared lamps, the thickness of the layer is 7 µ. This coated material is treated in the same way as in Example 1, with exposure to light from 2.5 seconds a satisfactory copy of the original examples obtained 10 to 20 The same results as in Example 9 are obtained if instead of there combination used the following combinations of copolymers and sensitizing Dyes are used: 10. Copolymer of N-vinylcarbazole and acrylonitrile - Rhodamine G, (C.I. 45 150).

11. Copolymer of N-vinylcarbazole and isopropenyl acetate - Bleu Basique pour Cuir N2B (C.I 51195).

12. Graft copolymer of N-vinylcarbazole and the terpolymer of vinyl chloride, vinyl acetate and maleic anhydride - brilliant.

Glacie Blue (C. 1. 42 140).

13. Graft copolymer of - N-vinylcarbazole and polyethyl acrylate-1-aminoanthraquinone.

14. Graft copolymer of N-vinylcarbazole and the terpolymer of vinyl chloride, vinyl acetate and vinyl alcohol tetracyanoethylene.

15. Copolymer of N-vinylcarbazole and 3,3 ', 5-trimethylisononyl ether - Monastral Fast -Green GS powder (C.I. 74 260).

16. Copolymer of N-vinyl carbazole and vinyl cinnamate - rhodamine 6 GH extra (C.I. 45 160).

17. Copolymer of N-vinylcarbazole and laurymethacrylate-rhodamine B (C. 1.45170).

18. Graft copolymer of N-vinylcarbazole and polystyrene - Victoria Blue (C. 1.44045).

19. Copolymer of N-vinyl carbazole and vinyl stearate - Monastral Fast Blue BVS Paste (C.I. 74 160).

20. Copolymer of N-vinylcarbazole and N-vinylpyrrolidone - Rhodamine B (C. 1.45170).

Example 21 A photographic barite paper base is used provided with a layer of a solution of the following composition: copolymer of N-vinylcarbazole and ethyl acrylate (produced by emulsion polymerization, as described above) 10 g methylene chloride .................................... 100 cm3 The dried layer is 8 µ thick and has a matt appearance; for this reason this electrophotographic material is well suited for document reproduction. After a negative charge due to a corona effect, the material becomes reflective exposed behind an original provided with an image on both sides. This is an exposure time when using a 100 watt lamp at a distance of 10 cm of 4 seconds is required. The latent image formed is dusted with a powder mixture of 100 parts of iron powder and 5 parts of the dye the Belgian patent 535 951 made visible. The powder image obtained is electrostatically transferred in a known manner to a writing paper and on This is fixed by heat, whereby a clear legible copy is obtained. By Addition of 15 mg Bleu Zapon Solide 3 G (CI. 51 005) to the above-mentioned solution the necessary exposure time can be reduced by half.

Example 22 A barytaized paper backing is made with one layer coated from a solution of the following composition: graft copolymer of N-vinyl carbazole and butyraldehyde acetal of polyvinyl alcohol as described above manufactured ............................................. 10 1-chloroanthraquinone .. 0.1 g of methylene chloride. . 100 cm3 The dry layer is 7 pt thick. After treatment as in the previous example, this material gives a after 3 seconds of exposure very strong copy.

Example 23 A paper backing of 70 g / m 2 is made with a baryte suspension coated by 10 parts of barium sulfate, 1 part of gelatin and 1 part of glycerin. To after calendering, this baryta layer is 10μ thick. A layer is made on them a solution of the following composition applied by immersion: copolymer of 2-ethylhexyl acrylate and N-vinylcarbazole 10 g of tetrahydrofuran ... 100 cm3 fuchsine Kiton G .. 12 mg After drying, the layer obtained is thick. If this material is treated in the same way as in Example 8 (exposure time 4 seconds), so you get an excellent copy.

Example 24 A photographic film coated with a baryta layer Paper backing of 120 g / m2 is covered with a layer of a solution of the following Composition: Copolymer of isobutyl methacrylate and N-vinyl carbazole (prepared as described above) 10 g methylene chloride ...................................... 100 cm3 Nile blue BB (C.I. 51185) 10 mg The dried layer is 8 p thick. That Material is charged and with a 100 watt lamp at a distance of 10 cm behind a transparent original exposed for 3 seconds. The exposed material is further developed as in Example 7.

Example 25 A barytaized paper backing is made with one layer provided from a solution of the following composition: copolymer of methyl methacrylate and N-vinylcarbazole, prepared as described above 90 g methylene chloride ...................................... 900 cm3 dioxane ............................................... 100 cm3 Rhodamine-B solution (l0lcig) in methylglycol 20 cm3. After drying, a smooth layer of 7 µ thickness. After charging, this layer is 5 seconds with a tungsten lamp of 100 watts exposed at a distance of 30 cm behind a negative. By Powder development gives a clear copy.

Example 26 A barytaized paper backing is made with one layer Coated from a solution of the following composition: Copolymer from Styrene, acrylonitrile and N-vinylcarbazole in a weight ratio of 50:30:20. . 10 g Methylene chloride .. 100 cm3 After drying, a layer is obtained whose mechanical and electrophotographic properties (e.g. tensile strength or sensitivity) are particularly good and the properties of layers far exceed those below Use of a mixture of 40% polystyrene, 30% polyacrylonitrile and 20% Poly (N-vinylcarbazole) were prepared.

Claims (2)

Claims: 1. Electrophotographic material made of a photoconductive Layer and one that is in intimate, superficial contact with this layer conductive base, characterized in that the photoconductive layer to more than 90 percent by weight of an organic polymeric substance with repeating There are structural units of the following general formula Ql Q2 CHR Z Z 'A CR' Q3 Q4, in which A denotes a single bond or one of the groups alkylene with 1 to 4 carbon atoms, -CO-, -O-CO-, alkylene-O-arylene, alkylene-COO-, alkylenarylene, Arylene, aroylalkylene, aroyl, carbamoyl, carbamoylalkylene, carbamoylarylene, Around R 'is a hydrogen atom or an alkyl radical having 1 to carbon atoms, and Z is a Sulfur atom or a single bond, Z 'a methine group or a nitrogen atom, Q1 and Q together represent the atoms required to close an aromatic nucleus and Qs and Q4 together are those necessary to close an aromatic nucleus Atoms, with the exception of a material containing a poly (N-vinylcarbazole). 2. Electrophotographic material according to claim 1, characterized in that that the photoconductive layer contains substances which increase the sensitivity. Documents considered: German Patent No. 1 068 115.